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Nonlinear local Lyapunov exponent and {1. predictability research

Science china Earth {1. 2006年第10期49卷 1111-1120页

作者： chen baohua1,{1.,2 & ding ruiqiang2 1. college of atmospheric sciences, lanzhou university, lanzhou 730000, china 2. State Key Laboratory of Numerical Modeling for atmospheric Science and Geophysical Fluid Dynamics (LASG), Institute of atmospheric Physics, Chinese Academy of sciences, Beijing 1.0029, china college of {1. sciences Lanzhou University Lanzhou China State Key Laboratory of Numerical Modeling for {1. Science and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

Because atmosphere itself is a nonlinear system and there exist some problems using the linearized equations to study the initial error growth, in this paper we try to use the error nonlinear growth theory to discuss its evolution, based on which we first put forward a new concept: nonlinear local Lyapunov exponent. It is quite different from the classic Lyapunov exponent because it may characterize the finite time error local average growth and its value depends on the initial condition, initial error, variables, evolution time, temporal and spatial scales. Based on its definition and the at-mospheric features, we provide a reasonable algorithm to the exponent for the experimental data, obtain the atmospheric initial error growth in finite time and gain the maximal prediction time. Lastly, taking 500 hPa height field as example, we discuss the application of the nonlinear local Lyapunov exponent in the study of atmospheric predictability and get some reliable results: atmospheric predictability has a distinct spatial structure. Overall, predictability shows a zonal distribution. Prediction time achieves the maximum over tropics, the second near the regions of Antarctic, it is also longer next to the Arctic and in subtropics and the mid-latitude the predictability is lowest. Particularly speaking, the average prediction time near the equation is 1. days and the maximum is located in the tropical Indian, Indonesia and the neighborhood, tropical eastern Pacific Ocean, on these regions the prediction time is about two weeks. Antarctic has a higher predictability than the neighboring latitudes and the prediction time is about 9 days. This feature is more obvious on Southern Hemispheric summer. In Arctic, the predictability is also higher than the one over mid-high latitudes but it is not pronounced as in Antarctic. Mid-high latitude of both Hemispheres (30°S―60°S, 30°―60°N) have the lowest predictability and the mean prediction time is just 3―4 d. In addition, predictab

关键词： nonlinear, local, Lyapunov exponent, atmospheric predictability, maximal prediction time.

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Application of the Conditional Nonlinear Local Lyapunov Exponent to Second-Kind Predictability

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Advances in atmospheric {1. 2024年第9期41卷 1769-1786页

作者： Ming ZHANG ruiqiang {1. Quanjia ZHONG jianping li Deyu LU State Key Laboratory of Earth Surface Processes and Resource Ecology(ESPRE)/Key Laboratory of Environmental Change and Natural Disasters of Chinese Ministry of EducationBeijing Normal UniversityBeijing 100875China Department of Ocean Science Hong Kong University of Science and TechnologyHong KongChina college of Oceanic and {1. sciences/Frontiers Science Center for Deep Ocean Multispheres and Earth System(DOMES)/Key Laboratory of Physical Oceanography Ministry of Education/Academy of the Future Ocean/Center for Ocean Carbon NeutralityOcean University of ChinaQingdao 266100China Laoshan Laboratory Qingdao 266237China State Key Laboratory of Numerical Modeling for {1. sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China college of Earth Science University of Chinese Academy of SciencesBeijing 100049China

In order to quantify the influence of external forcings on the predictability limit using observational data,the author introduced an algorithm of the conditional nonlinear local Lyapunov exponent(CNLLE)*** effectiveness of this algorithm is validated and compared with the nonlinear local Lyapunov exponent(NLLE)and signal-to-noise ratio methods using a coupled Lorenz *** results show that the CNLLE method is able to capture the slow error growth constrained by external forcings,therefore,it can quantify the predictability limit induced by the external *** this basis,a preliminary attempt was made to apply this method to measure the influence of ENSO on the predictability limit for both atmospheric and oceanic variable *** spatial distribution of the predictability limit induced by ENSO is similar to that arising from the initial conditions calculated by the NLLE *** similarity supports ENSO as the major predictable signal for weather and climate *** addition,a ratio of predictability limit(RPL)calculated by the CNLLE method to that calculated by the NLLE method was *** RPL larger than 1 indicates that the external forcings can significantly benefit the long-term predictability *** instance,ENSO can effectively extend the predictability limit arising from the initial conditions of sea surface temperature over the tropical Indian Ocean by approximately four months,as well as the predictability limit of sea level pressure over the eastern and western Pacific ***,the impact of ENSO on the geopotential height predictability limit is primarily confined to the troposphere.

关键词： conditional nonlinear local Lyapunov exponent second-kind predictability coupled Lorenz model ENSO

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The 2022 Extreme Heatwave in Shanghai,Lower Reaches of the Yangtze River Valley:Combined Influences of Multiscale Variabilities

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Advances in atmospheric {1. 2024年第4期41卷 593-607页

作者： Ping liANG Zhiqi ZHANG Yihui {1. Zeng-Zhen HU Qi chen Key Laboratory of Cities’Mitigation and Adaptation to Climate Change in Shanghai Shanghai Regional Climate CenterChina Meteorological AdministrationShanghai 200030China National Climate Center China Meteorological AdministrationBeijing 100081China Climate Prediction Center NCEP/NWS/NOAACollege ParkMD 20740USA

In the summer of 2022,china(especially the Yangtze River Valley,YRV)suffered its strongest heatwave(HW)event since *** this study,we examined the influences of multiscale variabi{1.ties on the 2022 extreme HW in the lower reaches of the YRV,focusing on the city of *** found that about 1.3 of the 2022 HW days in Shanghai can be attributed to the long-term warming trend of global *** mid-summer of 2022,an enhanced western Pacific subtropical high(WPSH)and anomalous double blockings over the Ural Mountains and Sea of Okhotsk,respectively,were associated with the persistently anomalous high pressure over the YRV,leading to the extreme *** Pacific Decadal Oscillation played a major role in the anomalous blocking pattern associated with the HW at the decadal time ***,the positive phase of the Atlantic Multidecadal Oscillation may have contributed to regulating the formation of the double-blocking *** warming of both the warm pool of the western Pacific and tropical North Atlantic at the interannual time scale may also have favored the persistency of the double blocking and the anomalously strong *** the subseasonal time scale,the anomalously frequent phases 2-5 of the canonical northward propagating variabi{1.ty of boreal summer intraseasonal oscillation associated with the anomalous propagation of a weak Madden-Ju{1.an Oscillation suppressed the convection over the YRV and also contributed to the ***,the 2022 extreme HW originated from multiscale forcing including both the c{1.mate warming trend and air-sea interaction at multiple time scales.

关键词： extreme heatwave multiscale variability air-sea interaction warming trend Yangtze River Valley Shanghai

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Real-world effectiveness of early insulin therapy on the incidence of cardiovascular events in newly diagnosed type 2 diabetes

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Signal Transduction and Targeted Therapy 2024年第7期9卷 2953-2959页

作者： Sihui Luo Xueying Zheng Wei Bao Sheng Nie Yu ding Tong Yue Yilun Zhou Ying Hu Hua {1. Qiongqiong Yang Qijun Wan Bicheng {1.u Hong Xu Guisen {1. Gang Xu Chunbo chen Huafeng {1.u Yongjun Shi Yan Zha Yaozhong Kong Guobin Su Ying Tang Mengchun Gong {1.nong Ji Fan Fan Hou jianping Weng Department of Endocrinology First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHeifeiChina Institute of Public Health {1. Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina Division of Nephrology National Clinical Research Center for Kidney DiseaseState Key Laboratory of Organ Failure ResearchNanfang HospitalSouthern Medical UniversityGuangzhouChina Department of Nephrology Beijing Tiantan HospitalCapital Medical UniversityBeijingChina The Second Affiliated Hospital of Zhejiang {1. School of Medicine HangzhouChina Sir Run Run Shaw Hospital Zhejiang University School of MedicineHangzhouChina Department of Nephrology Sun Yat-Sen Memorial HospitalSun Yat-Sen UniversityGuangzhouChina The Second People’s Hospital of Shenzhen Shenzhen UniversityShenzhenChina Institute of Nephrology Zhongda HospitalSoutheast University School of MedicineNanjingChina Children’s Hospital of Fudan university ShanghaiChina Renal Department and Institute of Nephrology Sichuan Provincial People’s HospitalSchool of MedicineUniversity of Electronic Science and Technology of ChinaSichuan Clinical Research Center for Kidney DiseasesChengduChina Division of Nephrology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina Department of Critical Care Medicine Maoming People’s HospitalMaomingChina Key Laboratory of Prevention and Management of Chronic Kidney Disease of Zhanjiang City Institute of NephrologyAffiliated Hospital of Guangdong Medical UniversityZhanjiangChina Huizhou Central People’s Hospital Sun Yat-Sen UniversityHuizhouChina Guizhou Provincial People’s Hospital Guizhou UniversityGuiyangChina Department of Nephrology the First People’s Hospital of FoshanFoshanChina Department of Nephrology Guangdong Provincial Hospital of Chinese Medicinethe Second Affiliated Hospitalthe Second Clinical CollegeGuangzhou University of Chinese Medicin

Early insulin therapy is capable to achieve glycemic control and restoreβ-cell function in newly diagnosed type 2 diabetes(T2D),but its effect on cardiovascular outcomes in these patients remains *** this nationwide real-world study,we analyzed electronic health record data from 1. medical centers across{1. between 1.January 2000,and 26 May *** included 5424 eligible patients(mean age 56 years,21.6 women/3248 men)who were diagnosed T2D within six months and did not have prior cardiovascular *** Cox regression models were used to estimate the associations of early insulin therapy(defined as the first-line therapy for at least two weeks in newly diagnosed T2D patients)with the incidence of major cardiovascular events including coronary heart disease(CHD),stroke,and hospitalization for heart failure(HF).During 1.,1.8 persons years of observation,we documented 834 incident CHD cases,71. stroke cases,and 230 hospitalized cases for *** diagnosed T2D patients who received early insulin therapy,compared with those who did not receive such treatment,had 31.lower risk of incident stroke,and 28%lower risk of hospitalization for *** significant difference in the risk of CHD was *** found similar results when repeating the aforesaid analysis in a propensity-score matched population of 4578 patients and with inverse probability of treatment weighting *** findings suggest that early insulin therapy in newly diagnosed T2D may have cardiovascular benefits by reducing the risk of incident stroke and hospitalization for HF.

关键词： cardiovascular treatment nationwide

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Fine particle trace elements at a mountain site in southern china:Source identification,transport,and health risks

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Journal of Environmental sciences 2024年第7期141卷 166-181页

作者： Jiaoping Xing Runping ding Feifeng {1. linyu Peng Wenhua Wang Xiaoyan Song Qing Ye Yuanqiu liu Key Laboratory of State Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed School of ForestryJiangxi Agricultural UniversityNanchang 330045China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China college of Geo{1. and Engineering North China University of Water Resources&Electric PowerZhengzhou 450046China

Trace elements in atmospheric particulate matter play a significant role in air qua{1.ty,human health,and biogeochemical *** this study,the trace elements(Ca,Al,K,Fe,Na,Mg,Zn,Pb,Mn,Ti,Cu,Cr,Sr,Ni)in PM2.5samples collected at the summit of *** were analyzed to quantify their abundance,source,transport,and health *** the whole samp{1.ng period,the major trace elements was Ca,Al,and *** the trace metals with the lowest concentrations were Sr,Ni,Rb,and *** trace elements were influenced by air mass transport routes,exhibiting an increasing trend of crustal elements in the northwesterly airmass and anthropogenic elements(Zn,Mn,Cu,and Ni)in the easterly air *** dust,coal+biomass burning,vehicle emission,urban nitrate-rich+urban waste incineration emissions,and soil dust+industry emissions were common sources of PM2.5on *** air mass transport routes had various source contribution *** results indicate that trace elements at *** are influenced by regional anthropogenic emissions and monsoon-dominated trace element *** total resulting cancer risk value that these elements posed were below the acceptable risk value of 1.1.^(-6),while the non-carcinogenic risk value(1.72)was higher than the safety level,suggesting that non-carcinogenic effects due to these trace elements inhalation were {1.kely to *** emission and coal+biomass burning were the common dominant sources of non-cancer risks posed by trace elements at ***.

关键词： Trace elements Risk assessment Cluster analysis Source apportionment

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人工智能技术在未来改进天气预报中的作用

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科学通报 2024年第17期69卷 2336-2343页

作者：黄建平陈斌西部生态安全省部共建协同创新中心兰州730000 兰州大学大气科学学院兰州730000

天气预报一直是一个复杂而充满挑战的领域.由于大气系统是高度非线性,即使极其微小的变化也可能对大气运动产生不可预知的扰动,这种大气中普遍存在的“蝴蝶效应”也正是天气预报的难点所在[1..长期以来,天气预报主要依赖于传统的数值天... 详细信息

天气预报一直是一个复杂而充满挑战的领域.由于大气系统是高度非线性,即使极其微小的变化也可能对大气运动产生不可预知的扰动,这种大气中普遍存在的“蝴蝶效应”也正是天气预报的难点所在[1..长期以来,天气预报主要依赖于传统的数值天气预报模型.随着具有非线性学习能力的深度学习技术的崛起,气象领域开始应用人工智能模型.人工智能(artificial intelligence,AI)模型在短时预报、气象图像处理以及气候模拟等在内的多个气象领域的应用均有重要的突破[2,3].

关键词：人工智能技术图像处理天气预报气象领域蝴蝶效应大气运动短时预报气候模拟

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The Relationship between Deterministic and Ensemble Mean Forecast Errors Revealed by Global and Local Attractor Radii

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Advances in atmospheric {1. 2019年第3期36卷 271-278,339页

作者： Jie FENG jianping {1. Jing ZHANG Deqiang {1.U ruiqiang ding School of Meteorology University of Oklahoma college of Global Change and Earth System Science (GCESS) Beijing Normal University Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and Technology Cooperative Institute for Research in the Atmosphere GSD/ESRL/OAR/NOAA Fujian Meteorological Observatory Wuyishan National Park Meteorological Observatory State Key Laboratory of Numerical Modeling for {1. sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Plateau Atmosphere and Environment Key Laboratory of Sichuan Province Chengdu University of Information Technology

It has been demonstrated that ensemble mean forecasts, in the context of the sample mean, have higher forecasting skill than deterministic(or single) forecasts. However, few studies have focused on quantifying the relationship between their forecast errors, especially in individual prediction cases. Clarification of the characteristics of deterministic and ensemble mean forecasts from the perspective of attractors of dynamical systems has also rarely been involved. In this paper, two attractor statistics—namely, the global and local attractor radii(GAR and LAR, respectively)—are applied to reveal the relationship between deterministic and ensemble mean forecast errors. The practical forecast experiments are implemented in a perfect model scenario with the Lorenz96 model as the numerical results for verification. The sample mean errors of deterministic and ensemble mean forecasts can be expressed by GAR and LAR, respectively, and their ratio is found to approach2^(1.2) with lead time. Meanwhile, the LAR can provide the expected ratio of the ensemble mean and deterministic forecast errors in individual cases.

关键词：吸引子半径集合预报集合平均预报误差饱和

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Relationships between the Extratropical ENSO Precursor and Leading Modes of {1. Variability in the Southern Hemisphere

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Advances in atmospheric {1. 2017年第3期34卷 360-370页

作者： Jianhuang QIN ruiqiang {1. Zhiwei WU jianping li Sen ZHAO Key Laboratory of Meteorological Disaster of Ministry of Education and Earth System Modeling Center Nanjing University of Information Science and Technology State Key Laboratory of Numerical Modeling for {1. sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences Plateau Atmosphere and Environment Key Laboratory of Sichuan Province Chengdu University of Information Technology Institute of atmospheric {1. Fudan University college of Global Change and Earth System {1. Beijing Normal University

Previous studies suggest that the atmospheric precursor of E1.Nifio-Southern Oscillation （ENSO） in the extratropical Southern Hemisphere （SH） might trigger a quadrapole sea surface temperature anomaly （SSTA） in the South Pacific and subsequently influence the following ENSO. Such a quadrapole SSTA is referred to as the South Pacific quadrapole （SPQ）. The present study investigated the relationships between the atmospheric precursor signal of ENSO and leading modes of atmospheric variability in the extratropical SH [including the SH annular mode （SAM）, the first Pacific-South America （PSA1. mode, and the second Pacific-South America （PSA2） mode]. The results showed that the atmospheric precursor signal in the extratropical SH basically exhibits a barotropic wavenumber-3 structure over the South Pacific and is significantly correlated with the SAM and the PSA2 mode during austral summer. Nevertheless, only the PSA2 mode was found to be a precursor for the following ENSO. It leads the SPQ-like SSTA by around one month, while the SAM and the PSA1.mode do not show any obvious linkage with either ENSO or the SPQ. This suggests that the PSA2 mode may provide a bridge between the preceding circulation anomalies over the extratropical SH and the following ENSO through the SPQ-like SSTA.

关键词： Pacific-South America atmospheric variabi{1.ty ENSO South Pacific quadrapole

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The Variability of Air-sea O_(2)Flux in CMIP6:Implications for Estimating Terrestrial and Oceanic Carbon Sinks

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Advances in atmospheric {1. 2022年第8期39卷 1271-1284,I0024-I0026页

作者： Changyu li {1. HUANG Lei ding Yu REN linli AN Xiaoyue liU Jiping HUANG college of {1. sciences Lanzhou UniversityLanzhou 730000China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China Enlightening Bioscience Research Center MississaugaL4X 2X7Canada

The measurement of atmospheric O_(2)concentrations and related oxygen budget have been used to estimate terrestrial and oceanic carbon ***,a discrepancy remains in assessments of O_(2)exchange between ocean and atmosphere(***-sea O_(2)flux),which is one of the major contributors to uncertainties in the O_(2)-based estimations of the carbon ***,we explore the variabi{1.ty of air-sea O_(2)flux with the use of outputs from Coupled Model Intercomparison Project phase 6(CMIP6).The simulated air-sea O_(2)flux exhibits an obvious warming-induced upward trend(~1.49 Tmol yr−2)since the mid-1.80s,accompanied by a strong decadal variabi{1.ty dominated by oceanic c{1.mate *** subsequently revise the O_(2)-based carbon uptakes in response to this changing air-sea O_(2)*** results show that,for the 1.90−2000 period,the averaged net ocean and land sinks are 2.1.±0.43 and 1.1.±0.52 GtC yr−1.respectively,overall consistent with estimates derived by the Global Carbon Project(GCP).An enhanced carbon uptake is found in both land and ocean after year 2000,reflecting the modification of carbon cycle under human *** derived from CMIP5 simulations also investigated in the study allow for comparisons from which we can see the vital importance of oxygen dataset on carbon uptake estimations.

关键词： air-sea O_(2)flux carbon budget land and ocean carbon sinks CMIP6

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面料堆垛非接触式分层吸附工艺模型与系统构建

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纺织学报 2024年第5期45卷 209-217页

作者：马梓鸿陈慧敏丁孟孟岳晓丽东华大学机械工程学院上海201620

针对因面料柔软、透气导致面料堆垛难以自动分层抓取、移送的问题,探讨了利用非接触式吸附技术进行面料堆垛分层的可行性。考虑面料悬垂特性、堆垛内气体流动压力损失和层间静电力等因素,构建了伯努利非接触式堆垛分层吸附力理论模型。... 详细信息

针对因面料柔软、透气导致面料堆垛难以自动分层抓取、移送的问题,探讨了利用非接触式吸附技术进行面料堆垛分层的可行性。考虑面料悬垂特性、堆垛内气体流动压力损失和层间静电力等因素,构建了伯努利非接触式堆垛分层吸附力理论模型。为验证该模型的有效性和非接触式吸附系统的可靠性,进行了吸附力测试以及面料堆垛分层吸附试验。结果表明,所构建的吸附力理论模型与通用模型的结果偏差为26.1.%;模型计算所得吸附力变化趋势与试验结果一致,数值与试验结果相差9.4%;利用模型计算所得工艺参数对面料堆垛进行分层吸附的成功率可达93%,所构建的吸附工艺模型与系统的有效性和可靠性较高。

关键词：服装生产面料堆垛非接触式吸附技术吸附力堆垛分层

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